[Iamscotticus]

I understand the coolant reservoir has changed for 2020-21?
Can someone post some pics from a 3.6?
Thanks

 

[Goodspike]

When I read the title of the thread I thought: Weird fetish. Then I saw who was posting. Now I'm surprised it wasn't a fetish request.

 

[Iamscotticus]

hey, man, lay off the hard stuff, OK?
LOL

 

[S2H]

Don’t get too excited over those curvaceous lumps, buddy. 😂

 

[Iamscotticus]

whoa, hey!

 

[C21964]

Part lookup does show a different part number for 2021. Internal baffling changed or added maybe?

 

[White016]

Part lookup does show a different part number for 2021. Internal baffling changed or added maybe?

Could be, there is an updated tank and TSB I read that helps keep air out of the system when it gets a tiny bit low.
Causes noise in the heater core.

 

[spectre6000]

I didn't realize that changed for '20, I thought I read '21. I read it here, so nothing personal to anyone in particular, but it's hardly authoritative. I'm curious to see a before and after, and if there's enough hard data to go on, a changeover date would be nice. In my past vehicular exploits, there have been entire books written about year to year (and month to month, week to week, and even day to day) changes. We don't have the numbers, coordination, or enthusiasm for such an endeavor, but it's always nice to know what's what in case something dies. Then you can get whatever the best version is going forward.

 

[Goodspike]

If the change was for a particular problem with the older design wouldn't the new part be showing up as a replacement part number when you ordered a reservoir for a 2019 and earlier model? (Assuming they didn't plan poorly and don't need to sell out a bunch of inventory.)

 

[JeffreyG]

Five years in to a model life cycle, the most common reason for a part change is cost savings. All the big problems discovered in the first year got fixed in years two and three. By now all they are doing is cheaping stuff out.

Plus the minor face lift.

 

[Iamscotticus]

Externally I don't see any obvious change.
That TSB would be helpful.

 

[White016]

Externally I don't see any obvious change.
That TSB would be helpful.

I searched for it, no luck, maybe I dreamt it?

 

[C21964]

I searched for it, no luck, maybe I dreamt it?

this: 19-NA-007 1..2 (nhtsa.gov)

 

[White016]

this: 19-NA-007 1..2 (nhtsa.gov)

Yes! @Iamscotticus

Thank you!

 

[Goodspike]

this: 19-NA-007 1..2 (nhtsa.gov)

So does this mean that the change started sometime in 2019? And how do you read VIN breakpoints?

My VIN starts 1GCPTC......, and the document indicates the breakpoint is 1GCPTB. . .. Since C is after B (the last letters I gave), does that mean mine is the newer version?

 

[Chuck_B]

View attachment 400091
Don’t get too excited over those curvaceous lumps, buddy. 😂

Oooooooooooooo...... Sweeeeeet................

 

[Iamscotticus]

this: 19-NA-007 1..2 (nhtsa.gov)

Mad skills!

 

[Iamscotticus]

OK,
having read the TSB.
Two things:
(1) The repair for air in the coolant line is replace the surge tank. This would be the course for any suspect broken surge tank.
(2) The TSB don't say that the surge tank was redesigned to address a design failure.

 

[Goodspike]

(2) The TSB don't say that the surge tank was redesigned to address a failure.

I asked earlier if it's a new/replacement part number. The link below would indicate that it is. Not only does it say "replaces" but it also is the part for 2015-2020. So presumably it is a change in design.

2015-2020 GM Expansion Tank 84388367 | GMPartsDirect.com

2015-2020 GM part # 84388367 - Expansion Tank

www.gmpartsdirect.com

Undoubtedly all this gurgling contributed to Consumer Reports downgrading the twins.

 

[Iamscotticus]

I could buy this theory, however, part numbers getting superceded is very common.